Urinary catheters have been used for many years both for patients recovering from surgery and for those who are incontinent. In patients recovering from bladder and prostate surgery blood clots and clumps of tissue and debris often form which require frequent periodic irrigation of the bladder. This irrigation is performed through the catheter and can cause a great deal of pain and discomfort to the patient.
After a catheter has been in place for more than three of four days there is an almost certainty of bacterial infection of the urinary tract which may eventually spread to the kidneys if the catheter must remain in place for extended periods. The infection has been attributed to microorganisms moving up through the drainage tube and into the lumen of the catheter and finally to the bladder. Microorganisms may also become trapped in the urethra where they can reproduce.
Little has been done to improve the catheter since the development of the well-known Foley Catheter which provides an inflatable balloon near its distal end to retain the catheter in the bladder. Goldman fitted his catheter with a rigid section to prevent collapse of the lumen when pressure is exerted to inflate the balloon (U.S. Pat. No. 2,819,718).
Several catheters have been developed which permit cleansing of the main lumen to reduce the chance of having bacteria enter the bladder, but the cleansing solution is not permitted to enter the bladder and has nothing to do with bladder irrigation. Godfrey, in U.S. Pat. No. 4,227,533 teaches a flushable urinary catheter fitted with a valve such that a cleansing solution can be used to flush the catheter but the solution cannot pass the valve to enter the bladder. The catheter is cleansed up to the point of the valve. Kay also provides for a catheter which is fitted with a cleansing unit. The drainage ports of the catheter can be closed when the cleansing solution is introduced. Here too the lumen of the catheter can be cleansed without the solution entering the bladder (U.S. Pat. No. 4,723,946).
Christopher, in U.S. Pat. Nos. 4,571,241 and 4,710,169, describes a catheter with a collapsable wall portion which inflates with the flow of urine. The urethra is only extended as is that portion of the catheter when there is a urine flow, so that bacteria do not have a constant access to the bladder. He also provides for antibacterial seals to prevent bacteria from entering the urinary tract.
Glassman has developed a catheter with grooves along the exterior wall through which a cleansing solution can irrigate the urethra. The solution is introduced into the catheter through an external tube which directs the solution through channels within the wall of the catheter and into the grooves through openings spaced along its length. The cleansing solution does not enter the bladder, nor does it cleanse the drainage lumen. (U.S. Pat. No. 4,579,554).
Sakamoto et al. in U.S. Pat. No. 4,642,104, teaches a process for affixing an antimicrobial substance to the exterior wall of a urinary catheter to effectively prevent urinary tract infection. The antimicrobial substance is effective over an extended period of time.
None of the above patents are for introduction of the irrigating solution into the bladder itself. Chen et al. in U.S. Pat. No. 4,904,245 has developed a valve assembly for urinary bladder irrigation. However, that system introduces the irrigating solution through the same channel used for drainage, thus pushing any material within the lumen of the catheter up into the bladder.
Morales et al. designed a catheter through which urine is drained from the bladder and which also delivers medication to the bladder through a separate central channel. This catheter is not indwelling and is removed after the medication has been dispensed. (U.S. Pat. No. 5,120,316)
Chaffin (U.S. Pat. No. 2,286,462) developed a surgical drainage and irrigation tube. The irrigating solution flows upwards on one arm of the tube, and down the other arm. Some of the solution can enter the surgical field, but it is the downward flow that creates mild suction to remove blood and other secretions from the field without creating negative pressures in the cavity or wound.
The instant invention proposes a catheter which can deliver an irrigating solution to the bladder, provide drainage of urine from the bladder and also maintain a mild suction to break up and remove clots and debris which may clog the drainage ports. The drainage lumen of the catheter is cleansed at the same time, thus lessening the chance of upward movement of bacterial therein.